“Roe v. Wade is an invitation to really celebrate women, women’s rights and women’s reproductive rights,” says Magalie Bonneau-Marcil, director of Oakland nonprofit Dancing without Borders, who will direct the Jan. 26 flash mob. She expects between 400 and 500 dancers to descend upon the plaza.

The performance is part of a larger event, Women Life & Liberty, organized to commemorate the landmark Supreme Court decision that made abortion legal in the United States. The Trust Women Silver Ribbon Campaign is organizing the free celebration in tandem with the National Organization for Women and a coalition of more than 20 local partners.

“Our sense was, it’s an opportunity to claim and reclaim, and revive our activism around the issues that this event is about,” Silver Ribbon Campaign Director Ellen Shaffer told the Guardian. The rally is part of a national effort that has also launched an “online march[3]” for reproductive rights.

Birth control champion Sandra Fluke, who became the center of a firestorm after being lambasted by Rush Limbaugh[4] for testifying before Congress on the need for access to birth control, will speak at the rally. Other speakers will include filmmaker and Webby Awards Founder Tiffany Shlain[5], and San Francisco Supes Malia Cohen, David Campos, David Chiu and Eric Mar, who joined the board in adopting a December resolution commemorating the 40th anniversary of Roe v. Wade.

Meanwhile, an international campaign to end violence against women will also play a role in this weekend’s events. Upon returning to the Bay Area after a dance festival in Europe, Bonneau-Marcil says she saw Eve Ensler’s music video promoting VDay’s 1 Billion Rising Campaign[6], created to spark a global movement to end violence against women. “I was so moved,” she says.

Inspired, she began making preparations for the Jan. 26 performance and an upcoming Feb. 14 flash mob, to be staged in front of San Francisco City Hall in league with VDay’s global movement.

With recent outrage fueled by the rape and fatal attack in India[7], the public performances are timely. Bonneau-Marcil describes the public dance gatherings as a way for participants to “share a prayer to create a world free of violence and sexual oppression.”

But there’s likely to be drama, as the Women Life & Liberty celebration is one of two dueling events. Walk for Life West, essentially the polar opposite of the Trust Women Silver Ribbon Campaign, is being spearheaded by San Francisco pro-lifers Dolores Meehan and Eva Muntean. Now in its ninth year, the annual event will bring hordes of anti-abortion activists to San Francisco, wielding dead fetus photos. They’ll travel from as far away as Nevada, Canada and “all over the Midwest,” according to Muntean. “We have 200 buses coming from all over the West Coast,” she said.

The anti-abortion rally will feature speakers such as Rev. Clenard Childress, who has built a career out of telling right wing Christians that the pro-choice movement is racist. (Seems Childress also spends his spare time penning inflammatory columns suggesting that acceptance of LGBT rights is “a sign of the end times[8].”)

The pro-life rally will converge at Civic Center Plaza and progress to – where else? – Justin Herman Plaza. There, according to the event page[9], revelers from the transformative flash mob may still be celebrating. Expect an awkward buzz kill.

This being San Francisco, plans are already being hatched to counter-protest the anti-abortion event. (Muntean emphasized that Walk for Life West should not be interpreted as counter-protest to the Women Life & Liberty event, by the way.)

Stop Patriarchy, made of up activists who are pro-choice, anti-Democratic party, and even anti-pornography since they deem it to be part of the war on women, plans to stage “boisterous and confrontational political protests throughout the week, taking on the Pro-Lifers who will be in San Francisco,” according to a press release. They’ll be there counter-protesting the Walk for Life with banners and signs declaring, “Abortion On Demand and Without Apology!”

Bonneau-Marcil, the flash mob director, says she’s trying to stay out of any back-and-forth that may come from warring factions. "We're not pointing fingers," she says. Instead, she's on a mission to help dancers move in harmony to “access a place where, it’s not about opinions. It’s just about remembering who we are as human beings."

The Women, Life & Liberty rally will be held at Justin Herman Plaza from 10 a.m. to noon. The Dancing Without Borders flash mob performance will take place at 11:30. Anyone can join the flash mob after attending two rehearsals: more info here[9]. The Walk for Life West rally will converge at 12:30 at Civic Center Plaza and begin the procession to Justin Herman at 1:30. More info here[10], here[11] and here[12].